The goal of this proposal is to investigate the principles and mechanisms by which the central nervous system organizes the regulation of body temperature. By analyzing and observing single unit activity in the preoptic anterior hypothalamic area and in the brainstem to changes in peripheral and central temperatures and by tracing their neural connections by electrical s stimulation in the hypothalamus and brainstem, we hope to produce two tangible results. a) To understand more fully the neural basis of PO/AH thermosensitivity, b) Information on the role of brainstem nuclei such as the raphe in modulating thermoregulatory function. Protocols for the testing of stated hypotheses in the proposal are outlined. BIBLIOGRAPHIC REFERENCES: Microelectrophoresis of prostagladin E1 onto single units in the hypothalamus of the rabbit. J.T. Stitt and J.D. Hardy. Am. J. Physiol., 229,240-245, 1975.